JPH04206511A - Coil device - Google Patents

Abstract

PURPOSE:To contrive improvement in thermal shock property by a method wherein the sag for alleviation of thermal stress is provided on the lead part which is used to connect a primary coil lead-out part to a primary terminal. CONSTITUTION:A wound primary coil 2 is inserted into the inner circumferential side of a secondary bobbin, they are placed in a case, insulating cast resin, consisting of thermosetting synthetic resin, is poured in and impregnated, the resin is heat-cured, a core is inserted therein, and a coil device is constituted. The primary coil 2 and primary terminals 12 and 13 are connected by the guide pin 15, which is integrally formed to the primary bobbin 1, in such a manner that they are formed in a homing manner maintaining a constant sag. This pin 15 is removed after homing, and insulating cast resin is poured, impregnated and hardened by heating.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention mainly relates to homing for preventing disconnection of a primary coil lead wire of an ignition coil for an internal combustion engine.

[Conventional technology]

Conventional coils start from the primary bobbin as in Japanese Patent Application No. 107079/1982. The primary coil lead wire had been crawled around for connection.

but. No consideration was given to alleviating the thermal stress applied to the primary coil lead wire.

[Problem to be solved by the invention]

The above conventional technology is. No consideration was given to alleviating the thermal stress applied to the primary coil lead, and the primary coil lead wire sometimes broke during thermal shock tests.

The present invention is designed to measure the difference in linear expansion coefficient between the primary coil lead part that extends around a bobbin made of thermoplastic synthetic resin and thermosetting synthetic resin. By providing slack in the primary coil lead wire to relieve thermal stress.

The purpose is to provide a coil device that absorbs heat and has excellent thermal shock resistance.

[Means to solve the problem]

To achieve the above purpose. The lead portion for connecting the primary coil lead-out portion to the primary terminal is provided with slack to alleviate thermal stress.゛To achieve the other objectives listed above. A guide pin for homing is provided on the primary bobbin or the secondary bobbin, and the guide pin is removed after homing to maintain a constant slack.

[Effect]

There is no guide pin for homing on the primary or secondary bobbin. Add some slack to the primary coil lead. This alleviates the thermal stress caused by the difference in linear expansion coefficient between the copper that is the lead wire of the 5 primary coil and the thermosetting resin.
Improves thermal shock resistance.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

For the primary bobbin 1. A primary coil 2 is wound around the secondary bobbin 3, and a secondary coil 4 is wound around the secondary bobbin 3. The primary bobbin 1 is molded from thermoplastic synthetic resin.

The primary coil 2 is made of enamelled wire with a wire diameter of about 0.3 to 1.01, which is applied several thousand times per layer, for a total of 100 to 20 times.
It has been laminated and wound about 0 times. The winding start and winding end of the primary coil 2 are tangential to the primary terminals 12' and 13, respectively.

The secondary bobbin 3 is. A plurality of flanges 5 are formed from the same synthetic resin as the primary bobbin 1 and arranged in the axial direction.
and a plurality of grooves 6 separated by a collar 5. The secondary coil 4 is wound approximately 10,000 to 15,000 times in total using enamelled wire with a wire diameter of approximately 0.03 to 0.1. It is connected together with the primary coil 2, and the end of the winding is connected to the high voltage terminal 9.

Case 7 is molded from thermoplastic synthetic resin,
At the time of molding, the metal tube 8 for tightening to the engine is integrally molded. Further, the high voltage terminal 9 is press-fitted after molding.

It was wrapped. The primary coil 2 is inserted into the inner circumferential side of the secondary bobbin 3, placed in a case 7, injected with insulating casting resin 10 made of thermosetting synthetic resin such as epoxy resin, and then heated and hardened. , into which an iron core 11 is inserted to form a coil device.

A primary coil 2 and a primary terminal 12, which constitute the main part 7 of the present invention.
As shown in FIG. 2, the connection 13 can be homed by a guide pin 15 formed integrally with the primary bobbin 1 so as to maintain a constant slack. This guide pin 15 is removed after homing, and then
is injected, impregnated, and heated to harden.

A thermal shock test (-5
5℃! ; 150° C. min/40 minutes each) As a result, the wire without walnuts broke at 200 to 300, but the wire with walnuts broke at 400 to 600. Therefore, it was confirmed that the life span was approximately doubled. Although the embodiment has been described with a structure in which the guide pin 15 is formed integrally with the primary bobbin 1, the guide pin 15 may also be formed integrally with the secondary bobbin 3. Also. A similar structure and effect can be obtained by providing a hole into which the guide pin 15 is inserted in the primary bobbin 1 or the secondary bobbin 3, inserting the guide pin 15 into the hole, homing it, and then removing the guide pin 15. I can do it.

〔Effect of the invention〕

According to the invention. This allows the primary coil lead to have a uniform lume. It is possible to alleviate the thermal stress caused by the difference in linear expansion coefficient between the copper that is the primary coil lead part and the thermosetting resin, and improve thermal shock resistance.

Furthermore, by providing a guide pin for homing, all products can be managed uniformly, which has the effect of eliminating variations in product life.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a split-wound molded ignition coil showing one embodiment of the present invention, and FIG. 2 is a three-dimensional view of the primary bobbin of the ignition coil. 1... Primary bobbin, 2... Primary coil, 3... Secondary bobbin, 4... Secondary coil, 5... Tsuba, 6...
Groove, 7... Case, 8... Metal tube, 9... High voltage terminal, 10... Insulating cast resin, 11... Iron core, 12.
13...Primary terminal, 14th 1t21 δ'' 2nd port

Claims (3)

[Claims] 1. Components such as the primary coil, secondary coil, and primary terminal are housed in a case pre-molded with thermoplastic synthetic resin, and thermosetting synthetic resin such as epoxy resin is injected into the case, hardened, and then insulated. A coil device characterized in that a lead portion for connecting the lead-out portion of the primary coil to the primary terminal has a slack for relaxing thermal stress. 2. In the coil device according to claim 1, the primary bobbin or the secondary bobbin is provided with a uniform slack in the primary coil draw-out portion and the lead portion for connecting the primary terminal. A coil characterized in that a guide pin for homing is provided integrally with the primary bobbin or the secondary bobbin, the guide pin is removed after the primary coil and the primary terminal are connected, and a thermosetting synthetic resin such as epoxy resin is injected and hardened. Device. 3. In the coil device according to claim 1, the primary bobbin or the secondary bobbin is provided with a uniform slack in the primary coil draw-out portion and the lead portion for connecting the primary terminal.
A hole is made to insert a guide pin for homing, and when connecting the primary coil and primary terminal, the guide pin is used to provide a certain amount of slack, then the guide pin is removed and thermosetting synthetic resin such as epoxy resin is injected. , a coil device characterized by being hardened.